Chuck collet



O. M. MULLER CHUCK COLLET )77. WM//f /NveNTor www CCM b a C Y a b A 4 M e y ma! f l f f-; f.// /a d C L@ k Get. 3, 1933.

Patented oef. 3,1933

UNITED STATES PATENT OFFICE Application April 25, 1929, serial No. 358,121, andl in Germany May 2, 1928 My invention relates to collets lor chucks. It is an object of my invention to eliminate the troubles connected with the hardening of collets and to this end I design the collet with a continul ous work-engaging face.

' The usual collets are made with longitudinal slots extending radially from the inner to the outer perimeter of the collet. By machining such slots tensions are set up which cause distortion l of the tongues intermediate the slots upon hardening. Such irregularities cannot be made up for by grinding so that the tongues extend at various positions with respect to the axis of the collet and the work is not chucked in an exactly i coaxial position.

It has been proposed to overcome this tendency to distortion by leaving small webs in the slots which are broken after hardening the collet, but in most cases distortion will occur notwithstanding on account of latent stress. f My invention may be reduced to practice in .various ways as will be described/ in full detail below. Thus, I may provide a collet in the shape of a solid part throughout, or I may recess it on the outside or the inside, or both, but in any case its work-engaging face which may be on the inside or on the outside of the collet, must be continuous. The work to be chucked in the collet may be solid, and inserted inthe collet, or it 3o ingybgpouoglitn the couet'inserted in the work. Pressure is erted on the collet from Without or within, as the case may be, to apply its work-engagingv face to the work. The workengaging face is continuous, that is, unbroken by slots or gaps.

A member having some similarity to rny'collet has already been proposed for a thread gage in which the gaging member is applied to the plug to be tested-by placing an orifice in the member on the plug, and exerting pressure onwthe member by which the 'diameter of the orioe is reduced- .This member is undivided like my collet but the face of the member which corresponds to the work-engaging face in my collet is not continuous but interrupted by radial gaps or slots extending from its oriiicel In the accompanying drawing several types of collets embodying my invention are/ illustrated diagrammatically by way oi' example.

In the drawing Fig. 1 is a section of a chuck with a solid collet having a single tapered part and adapted to engage the work on the outside,

- Fig. 2 is a section of a chuck having a similar collet but with two tapered parts,

3 is 'a section o! a collet adapted to engage the work on the inside,

Fig. 4 is an end elevation of the collet in Fig. 3, viewed from the left, and

Fig. 5 is an end elevation of a collet having 60 recesses on 'the outside.

Referring now to Fig. 1, d is a spindle having a threaded end e, b is a collar seated on the threaded end and having a hollow taper at its front, a is a solid, that is, unrecessed and unslotted, collet 05 seated in the taper, and f is a stem on the rear end of the collet which nts an axial bore in theY spindle d.

Referring to Fig. 2, t is the collet having two tapered ends g and h which is inserted in a hollow taper at the front end of the spindle d, and c is a tapered liner in the spindle for lholding the tapered rear end y of the collet. i

The collets shown are for work which is en` gaged on the outside, being inserted in the bore or recessof the collet a' or t. Referring to Figs.

3 and 4, these show a collet lor a hollow work,

i being the collet, lc being a taper on a spindle or mandrel on which the collet is seatd,and lbeingp a nut for exerting thrust on the collet so as to 30 force it into the work. l With solid collets as shown deformation under thrust is relied on for chucking th work and this `is suilicient for work machined to narrow limits,

and the work will be held in an exactly axial position as the tapers beingl unslotted may be machined very exactlyl If itis desired to provide a collet of comparatively thicksection but which notwithstanding this is resilient enough the serrated type shown in Fig. 5 is adopted.

The collet m is serrated at n on the outside,and the continuous inner face of the collet engages the work, as in the cpllets shown in Figs. 1 and 2 where the work is inserted in the collet, but in a collet like that shown in Figures 3` and 4 where the work is supported on the outer face of the collet the serrations are on the inner face, the outer face being continuous Afor engaging the work.

It is to be noted that the tapered engaging surfacey opposite the/work engaging surface of each collet body is reduced leaving a relatively thin portion adjacent the tapered portion, the purpose being to increase the resilient action of the collet body-a when the'same is being applied in a working position.

I claim: 1. A chuck collet including a. body having a cylindrical continuous work engaging surface, and

having the opposite surface tapered and reduced toward the longitudinal axis to increase the inherent resiliency of the body and facilitate a i effective clamping action.

2. A device of the character described comprising in combination, a rotatable supporting member, a collet associated with the-supporting member and including a body having a continuous cylindrical work engaging surface and having the OTTOMAXMLLER.` 

